Transporter for sample tubes



May 12, 1970 A. R. JONES TRANSPORTER FOR SAMPLE TUBES 2 Sheets-Sheet 1Filed Dec. .5, 1967 I N VEN TOR IIIIIII ALAN RICHARDSON JONESRECIRCULATING F PUMP a HEATER May 12, 1970 A. R. JONES 3,511,613

TRANSPORTER FOR SAMPLE TUBES v Filed Dec. 5, 1967 v 2 Sheets-Sheet 2MOTOR FIG?) (0 m E INVENTOR.

ALAN RICHARDSON JONES United States Patent US. Cl. 23-259 15 ClaimsABSTRACT OF THE DISCLOSURE A sample tube transporter which isparticularly suited for use in conjunction with automatic chemicalanalysis equipment. The transporter includes a frame having an endlesshorizontal channel in which a multiplicity of vertical sleeves areintermittently advanced in single file. Each sleeve is adapted toreceive a sample tube and thereby transport the tube through a pluralityof stations along the channel where treatment and analytical steps maybe performed. The contents of the sample tubes are maintained atconstant temperature and after such tubes have been transported throughall of the treating and analyzing stations such tubes and theirremaining contents are automatically discarded.

BACKGROUND While transport mechanisms for automatic analysis equipmentare known, such mechanisms are generally complex in structure andoperation and are subject to problems of maladjustment and breakdown. Inone such construction, measured amounts of samples are automaticallytransferred from sample tubes to conditioning tubes or cavities, thelatter tubes or cavities requiring emptying and washing followingconditioning and analyzing steps. While washing of the tubes may beperformed automatically, such a procedure not only increases thecomplexity of the apparatus but also introduces a possible source ofsample contamination.

While the importance of maintaining precise temperature control oversamples has been recognized, the difiiculties of maintaining suchcontrol in existing equipment are substantial because of the complexityof such equipment and because certain of the operations, such as theautomatic washing procedures mentioned above, may tend to interfere withprecise temperature adjustments.

SUMMARY An important aspect of the present invention lies in providing atransporter of relatively uncomplicated construction and operation whichis highly dependable in performance. and which thereby overcomes majordisadvantages of prior constructions. Each sample tube is guided alongan endless path by a plastic sleeve which slidably receives the tube. Anendless chain of such sleeves are intermittently advanced along saidpath, the sleeves being in lateral engagement with each other. Drivingforce exerted against one of the sleeves is thereby transmitted to allof the sleeves in the chain and, hence, to any and all of the sampletubes received in the openings of such sleeves.

The bottom ends of the sample tubes slide upon the smooth surface of ahorizontal platform which is submerged in a constant-temperature liquidbath. When the travel of a tube approaches a complete revolution of thecircuit, its guiding sleeve passes over a discharge chute and thedisposable sample tube and its contents are automatically discharged.

3,511,613 Patented May 12, 1970 THE DRAWINGS FIG. 1 is a perspectiveview illustrating a transporter in operative condition mounted in thetable surface of an automatic analyzer;

FIG. 2 is an exploded perspective view, shown partiallydiagrammatically, illustrating the components of the transporter;

'FIG. 3 is an enlarged vertical sectional view taken along line 33 ofFIG. 1;

FIG. 4 is an enlarged longitudinal sectional view taken along line 44 ofFIG. 1.

DESCRIPTION FIG. 1 illustrates the transporter 10 recessed into the topsurface 11 of a cabinet or console which also houses other components ofan automatic chemical analyzer. FIG. 2 more fully illustrates the majorcomponents of the transporter consisting of a frame A, a container B,drive means C and heating means D. Sleeve elements E and sample tubes Fare omitted from FIG. 2 for clarity of illustration but such elementsare shown fully in FIGS. 1, 3 and 4.

The frame includes a horizontal bottom platform 12, a top plate 13 andan intermediate plate 14. All three elements are securely connectedtogether in spaced parallel relation by vertical posts 15 eachconsisting of a bolt 15a and a pair of tubular spacers 15b and 15c (FIG.3). Each of the plates 13 and 14 has an elongated central opening 16 and17 therein. Within each opening is a horizontally elongated plate member18 and 19, the two plate members or islands being secured together inspaced parallel relation, and being affixed to platform 12, by posts 20which are similar in construction to posts 15. Member 18 is disposed inthe same horizontal plane as top plate 13, and member 19 in the sameplane as intermediate plate 14.

Within the openings 16 and 17 of the superimposed plates 13 and 14, andat one end of the island formed by members 18 and 19, is an upstandingshaft 21 equipped with star wheels 22 and 23 disposed at the same levelsas plates 13 and 14, respectively (FIG. 3). Shaft 21 extends downwardlythrough an opening 24 in the platform and, together with motor 25 whichis suit ably mounted beneath the frame, comprises the driving means Cfor advancing sleeves E and tubes F.

The edges of plates 13 and 14 which define openings 16 and 17, and thelateral edges of members 18 and 19 and of star wheels 22 and 23, form anendless elongated channel or passage 26 of substantially uniform widthfor slidably receiving the sleeve members E which in turn looselyreceive the sample tubes F. Referring to FIGS. 3 and 4, it will beobserved that each sleeve member E is generally cylindrical in shape,having end portions 27 of reduced diameter and an enlarged central orshoulder portion 28. The external diameter of end portions 27 isslightly less than the width of channel 26, whereas the shoulder portion28 is of greater diameter than the channel and has axial verticaldimensions just slightly less than the distance between plates 13 and14. Thus, the cylindrical sleeves are restrained against verticalmovement with respect to the frame but are free to move horizontallyalong the channel 26. Each of the sleeve members has a vertical bore 29extending completely therethrough, the bore having a diameter slightlylarger than that of the sample tube F loosely received therein.

The sleeve members 28 may be formed of any suitable material. It hasbeen found, however, that particularly effective results are obtainedwhere the sleeves are formed from tetrafluoroethylene resin because ofthe solvent and chemical resistance of such material and, in particular,

its low co-eflicient of friction. Plate members 13 and 14 are preferablyformed of metal, such as stainless steel, and sample tubes F are formedof glass. As will be brought out more fully hereinafter, the cylindricalsleeves 28 are in sliding contact with both the tubes and the plates;therefore, by forming such sleeves from tetrafiuoroethylene resin aself-lubricating assembly is obtained.

FIGS. 1 and 4 reveal that the parallel sleeves E are in side-by-sidecontact with each other to form an endless chain of such sleeves alonghorizontal channel 26. While a series of 34 of such sleeves isillustrated in FIG. 1, it will be understood that a greater or smallernumber might be provided, depending on the size of the transport unit asa whole and on the type of tests to be performed in the analyzer. Therecesses of the star wheels or sprockets 22 and 23 conform to thecurvature of sleeves E so that such sleeves may be received in andadvanced by the recesses. The driving force transmitted by the starwheels against the leading sleevethat is, the sleeve about to bereleased from the sprocket recessesis transmitted by such sleeve to thesleeve directly in front of it, that sleeve in turn pushing the onedirectly before it, and so on. Thus, even though there is no positiveconnection between the multiple sleeves of the chain, all of the sleevesare constrained by the plates 13, 14, 18, and 19 against movement in anydirection except along channel 26 and are advanced along the channel bya pushing force transmitted throuhg the chain and originating with thesleeve or sleeves in engagement with the sprocket assembly.

The entire frame A is disposed in container B with platform 12 submergedin a body of water or other liquid 30 disposed in the container (FIGS. 3and 4). Specifically, the platform is disposed far enough below thesurface of the liquid so that sample tubes F resting upon the plat formwill have their lower portions disposed in the liquid bath.Recirculating and heating means D of any conventional constructionserves to maintain the bath at constant temperature. As shown in FIG. 2,a drain tube 31 extends upwardly from the bottom of the container to thedesired level of the liquid; any liquid overflowing the top of the tubeis heated to a preselected temperature and is returned to the containerthrough inlet tube 32. By constantly recirculating the fluid in thecontainer, the temperature of the bath, and of the samples containedwithin tubes F, may be precisely controlled.

At the opposite end of the elongated container is an upstanding tube 33which is coaxial with drive shaft 21 and which, as shown in FIG. 3,projects above the level of bath 30. The tube is welded or otherwisesuitably sealed to the bottom of the container about an opening 34 inthe bottom wall through which shaft 21 extends.

Adjacent to upstanding tube 33 is a second tube 35 which, like tube 33,has its upper end disposed above the level of bath 30. Tube 35 extendsupwardly through the bottom Wall of the container and through an opening36 in platform 12, and constitutes one element of a sample tubedischarge chute assembly. Tube 35 is of larger internal diameter thanthe outside diameter of each sample tube F and is disposed directly inthe path of movement of such sample tubes as they advance along channel26. A ramp 37 also extends along the path of movement of the tubes inadvance of discharge tube 35 and, as shown in FIG. 4, slopes upwardlyfrom the surface of platform 12 to which it is secured to the top ofdischarge tube 35.

In the operation of the transport, a technician first places a sampletube F into a sleeve at the position indicated by an arrow or otherindicia 38- affixed to top plate 13 (FIG. 1). The intermittent drive ofthe unit advances the tube along the channel in a counterclockwisedirection as viewed in FIG. 1. As the tube'is so advanced, it passesthrough different stations where suitable reagents may be added throughfeed tubes 39, 40, and 41, depending upon the particular test involvedand upon the programming of the unit as a whole. Finally, after the tubehas nearly completed the circuit, it passes beneath an extraction device42 which is adapted to withdraw at least a portion of the contents ofthe tube for automatic chemical analysis. Thereafter, the sample tuberides upwardly upon ramp 37 until it is positioned directly over thedischarge chute 35 and drops through the chute into a suitable wastereceiver 43. The empty sleeve E then returns to the starting positionwhere the operator may insert a new sample tube and the entire cycle ofoperation is repeated.

It will be observed that each of the sample tu-bes F rides or slidesupon the smooth top surface of platform 12 and is therefore maintainedin its vertical position throughout nearly the entire cycle by thatplatform. The channel-defining plates 13, 14, 18, and 19 serve to guidethe sleeves and sample tubes in horizontal directions while the platformand ramp 37 control the vertical positioning of the sample tubes.

While in the foregoing I have disclosed an embodiment of the inventionin considerable detail for purposes of illustration, it will beunderstood by those skilled in the art that many of these details may bevaried without departing from the spirit and scope of the invention.

I claim:

1. A transporter for sample tubes in chemical analysis equipmentcomprising a frame having horizontal members defining an endlesshorizontal channel of uniform width; a plurality of sleeves each havingan opening extending vertical therethrough and having an externaldimension slightly less than the width of said channel; said sleevesbeing constrained by said frame only for movement along said channel andengaging each other in single file to form an endless chain of sleevesalong said channel; driving means successively engageable with eachsleeve to advance the same along said channel, the driving force exertedby said means against any one of said sleeves being transmitted bymutual engagement of said sleeves to all of the sleeves in said chain;said sleeves each being adapted to loosely and removably receive asample tube in the vertical opening thereof.

2. The structure of claim 1 in which sample tubes are loosely andremovably received in the openings of said sleeves; and platform meansprovided by said frame beneath said horizontal members for slidablysupporting the bottom ends of said sample tubes as the same are advancedalong said channel.

3. The structure of claim 1 in which said sleeves are generallycylindrical in shape.

4. The structure of claim 3 in which each of said cylindrical sleeves isprovided with an external shoulder of greater width than said channel;said horizontal frame members including spaced horizontal platesdisposed above and below the shoulder of each cylindrical sleeve;whereby said cylindrical sleeves are restrained against verticalmovement relative to said frame.

5. The structure of claim 1 in which said channel is in the shape of anelongated endless track.

6. The structure of claim 3 in which said driving means includes a starwheel rotatable about a vertical axis and engageable with each of saidcylindrical sleeves as they advance along said channel.

7. The structure of claim 1 in which said sleeves are formed oftetrafluoroethylene resin.

8. The structure of claim 2 in which said frame is provided with asample tube discharge opening at a selected point along the path oftravel of said sample tubes for the sequential release from said sleevesof sample tubes advanced along said channel.

9. The structure of claim 8 in which said frame is disposed in anopen-topped container supporting a body of liquid having a levelsubstantially :above the surface of said platform means; a tubulardischarge chute extending upwardly through said opening in said platformto a point above the level of the liquid body in said container; andramp means for guiding the lower ends of sample tubes from the level ofsaid platform to the open upper end of said tubular chute as said sampletubes are advanced along said channel.

10. The structure of claim 9 in which means are provided for maintainingsaid liquid Within said container at a constant pre-selectedtemperature.

11. A transporter for sample tubes in chemical analysis equipmentcomprising a frame having members defining an elongated horizontalchannel of uniform width; a plurality of vertical cylinders havingopenings extending axially therethrough and each having an externaldimension slightly narrower than said channel; said cylinders engagingeach other in single-file relation and being constrained by said framefor horizontal movement along said channel; means for advancing saidcylinders along said channel; a platform spaced below said members andproviding a smooth horizontal surface for slidably supporting the lowerends of upstanding sample tubes loosely received in said cylinders; anda tube discharge chute through said platform at a selected point alongsaid channel for the sequential release from said cylinders of sampletubes advanced along said channel.

12. The structure of claim 11 in which said frame is disposed in anopen-topped container supporting a body of liquid having a levelsubstantially above the surface of said platform; said discharge chutecomprising an opening in said platform, a vertical tubular member havingits lower end sealed to said platform about the edges of said platformopening and having its open upper end disposed above the level of saidliquid, and ramp means for guiding the lower ends of sample tubes fromthe level of said platform to the open upper end of said tubular memberas said tubes are advanced along said channel.

13. The structure of claim 12 in which means are provided formaintaining said liquid within said container at a constant pre-selectedtemperature.

14. The structure of claim 11 in which each of said cylinders isprovided with an external shoulder of greater width than said channel;said frame members comprising vertically-spaced plates disposed aboveand below the shoulders of each cylinder; whereby said cylinders arerestrained against vertical movement relative to said frame.

15. The structure of claim 11 in which said cylinders are formed oftetrafluoroethylene resin.

References Cited UNITED STATES PATENTS 3,202,188 8/1965 Allington 1411303,410,321 11/1968 Mitchell 141-130 3,432,271 3/1969 Wasilewski 23-259 X3,441,383 4/1969 Moore et al. 232S9 X MORRIS O. WOLK, Primary ExaminerR. E. SERWIN, Assistant Examiner US. Cl. X.Rv

